Those on a quest to rethink small-space living build tiny houses, install pop-up rentals on vacant lots, and design portable 10-square-foot microkitchens tucked inside armoires. Presented over the weekend at Toronto’s Interior Design Show, Cubitat is a 10-by-10-by-10-foot cube that houses a kitchen, bathroom, bed, laundry, and storage. Once plumbing and electric are hooked...